Oh, dear....not THE tire discussion, please....but for a long trip you'll have peace of mind, so suggest you do replace them.
So when you have everything done to the trailer and tow vehicle, this is when you need to gather all the medical info and contact numbers + all meds and definitely any serious health issues. Put that into your computer and when you leave for a trip, print it out and take it with you. On a longer trip a few years ago I lost all vision....yes, that was ALL. DH stopped, called 911 and they got me to the nearest hospital. By then my vision had returned. As it happened, being gone for more than one week, we'd tossed all our meds into bags to resupply those "old people" pill cases. If we'd not had everything with us, DH would have had no clue what I take and I most likely would not have remembered everything. Turned out it was a BP that bottomed out without any warning....change in meds recently. Lesson learned. I have a complete record in our computer and before any trip, update and put into a red ICE folder. A DF who is an EMT also suggests listing important contacts in your phone with the ICE prefix....emergency responders know to look.
Have a great trip.